On the one hand, the invention relates to a method for weaving face-to-face fabrics on a face-to-face weaving machine, the fabrics consisting of weft yarns, ground warp yarns and pile warp yarns, and one or several spacers being provided in order to keep the fabrics at a distance from one another during the weaving process, and a weaving reed being provided comprising reed dents, through which the said ground warp yarns and pile warp yarns are extending, and through which the spacers are extending every two or more reed dents.
Furthermore, the invention relates to a fabric, consisting of weft yarns, ground warp yarns and pile warp yarns and to a face-to-face weaving machine for weaving face-to-face fabrics consisting of weft yarns, ground warp yarns and pile warp yarns.
More specifically, the invention relates to a method for weaving shaggy fabrics.
Shaggy, fabrics, likewise called shag fabrics, are fabrics in which long coarse pile warp yarns are used. The pile height ranges from 15 mm to 100 mm. The thickness of the yarns is starting from 3000 denier and may reach 12000 deniers and even 30000 denier. Sometimes, for such shaggy fabrics, also yarns are used in which a thick and a thin yarn are united to form one single yarn in order to create additional effects,
Today, shaggy fabrics are mainly made of wool, hand-tufted or woven on single fabric weaving machines such as rod weaving machines or Axminster weaving machines. Such fabrics, however, are not suitable for being produced on a face-to-face weaving machine, as it is not always possible to interweave the thick pile warp yarns in the usual 2-and 3-shot weave as it is difficult to conceal the thick pile warp yarns in the fabric and as in fabrics made with a longer pile height (over 30 mm) there is the disadvantage that the pile retention leaves much to be desired and the quantity of yarn to be supplied, within one operating cycle of the machine, by the bobbin on the weaving rack will become too large because of the pile moving from the upper to the lower fabric. Moreover, the disadvantage mentioned last will cause a heavy load on the Jacquard machine, depending on the pattern to be woven.
In a single fabric rod weaving machine, these problems are less frequent, as the quantity of pile warp yarns that have to be supplied within one machine cycle is more limited, because only one fabric is woven and, moreover, the speed of the machine is lower. Also, when weaving on an Axminster weaving machine, these problems are less frequent, as the pile warp yarn have to be supplied for only one fabric, the weaving speed is lower and only one pile is inserted every three wefts. Furthermore, there are no problems either, caused by a dead pile.
Both single fabric rod weaving and Axminster weaving, however, have a significantly lower weaving efficiency than face-to-face weaving. Moreover, with none of these techniques it will be possible at the present time to produce shaggy or tufted fabrics by means of the cheaper yarns made of synthetic material or polypropylene.
To a man skilled in the art, it is not obvious to weave the thick yarns made of wool or polypropylene in several colors or with a long pile when making use of a face-to-face weaving technique. When using a Jacquard-weaving method with several colors and/or effects on a face-to-face weaving machine, each warp yarn system will comprise the various pile warp yarns having the various colors or effects, together with the ground warp yarns used to form the backing fabrics. In order to keep the upper and the lower fabric at a certain distance from one another, in face-to-face double-rapier weaving, spacers are used, likewise called lancets.
In most cases the number of warp yarn systems is corresponding with the number of reed dents of the weaving reed and each dent in the weaving reed comprises the said backing and pile warp yarns, as well as the spacer. In the event of shaggy fabrics, in which thicker yarns are used, the problem is that, within the reed dent, the thicker pile warp yarns will collide, mutually as well as with the ground warp yarns and with the spacer, when they have to take up their positions to form the shed desired in accordance with the pattern to be formed. This may cause several yarns to become entangled or warp yarns and spacers to get stuck in the reed dent. It may be possible to limit this risk by using a lower density of the reed, to reduce the number of reed dents, or using less colors or yarns that are less thick.
It is already known not to use the spacer in each warp yarn system or in each reed dent. Thus it will be possible to reduce the risk because the problem may occur only in part of the warp yarn systems, but the problem still exists and may still occur.